The radiation Therapy Oncology Group (RTOG) was organized in 1971 as a group of research and clinical centers dedicated to conducting clinical trials on the premise that a cooperative approach to the design and conduct of such trials would be of significant benefit to a large patient population. The RTOG is dedicated to the goal of improving the care of patients with malignant disease and increasing their survival rate through research and multidisciplinary study. The RTOG's objectives are: To constitute a group of clinical radiation therapy investigative centers dedicated to cooperative clinical trials; to define clinical priorities for radiation therapy studies and establish standardized treatment parameters; and to define radiation and ancillary equipment needs for clinical trials. The RTOG develops strategies for treatment of all types of tumors and stages for various sites.